Complex antenna systems are typically assembled from a combination of radiating elements, reflectors, and ground planes. Radiating elements are typically attached to reflectors or ground planes by bolting or similar mechanical methods wherein electrical coupling between components is achieved through conductor-to-conductor contact.
The inventors discovered the following: conductor-to-conductor contact is undesirable in applications in which passive inter-modulation (PIM) is of concern. Electrical coupling by conductor-to-conductor contact can produce PIM in antenna systems that transmit a plurality of signals. Radio frequency (RF) currents flow on the surfaces of reflectors and ground planes. PIM products arise because conductor-to-conductor contacts exhibit non-linear electrical behavior, arising, for example, from corrosion of the metal surfaces in the contact region.